Jonathan M Crowell

US Patent:

7512036, Mar 31, 2009

Filed:

Aug 15, 2006

Appl. No.:

11/464579

Inventors:

Jonathan C. Crowell - Dorchester MA, US

Assignee:

Ocean Server Technology, Inc. - Fall River MA

International Classification:

G01S 3/80

US Classification:

367127

Abstract:

A method for determining the position of an underwater device includes placement of a plurality of station keeping devices on or below the surface of the water in known positions. A device to locate is provided for placement below the surface of the water, and the device to locate and the station keeping devices are provided with a synchronized time base and a common acoustic pulse time schedule. Each station keeping device sends an acoustic pulse at a time according to the common acoustic pulse schedule. The device to locate receives pulses sent by the station keeping devices and calculates a distance between itself and each station keeping device based upon the time that the acoustic pulse is sent and the time that the pulse is received. The device to locate then calculates its position based upon the distances between the device to locate and the station keeping devices. Systems and devices are also disclosed.

US Patent:

8009516, Aug 30, 2011

Filed:

Feb 17, 2009

Appl. No.:

12/372065

Inventors:

Jonathan C. Crowell - Dorchester MA, US

Assignee:

Ocean Server Technology, Inc. - Fall River MA

International Classification:

G01S 3/80

US Classification:

367128

Abstract:

A method for determining the position of an underwater device includes placement of a plurality of station keeping devices on or below the surface of the water in known positions. A device to locate is provided for placement below the surface of the water, and the device to locate and the station keeping devices are provided with a synchronized time base and a common acoustic pulse time schedule. Each station keeping device sends an acoustic pulse at a time according to the common acoustic pulse schedule. The device to locate receives pulses sent by the station keeping devices and calculates a distance between itself and each station keeping device based upon the time that the acoustic pulse is sent and the time that the pulse is received. The device to locate then calculates its position based upon the distances between the device to locate and the station keeping devices.

US Patent:

8448592, May 28, 2013

Filed:

Oct 28, 2008

Appl. No.:

12/259570

Inventors:

Jonathan C. Crowell - Dorchester MA, US
David Charles - Franklin MA, US

Assignee:

Ocean Server Technology, Inc. - Fall River MA

International Classification:

B63B 45/04
B63C 7/26
B63G 8/24
B63G 8/42
B60Q 1/52

US Classification:

114322, 114326, 114329, 114330, 114336, 116 26, 116209

Abstract:

Methods and devices are provided for rescuing and recovering underwater vehicles. In one embodiment, a system is provided that includes a modular rescue device configured to attach to an underwater vehicle, such as with a tow line. The rescue device can include one or more emergency mechanisms that can be automatically and/or manually activated to aid in detecting the location of the underwater vehicle in the event of an emergency. One exemplary emergency mechanism includes a buoyancy mechanism, e. g. , an expandable lift bag, configured to be inflated with a fluid to add buoyancy force to the system to pull the underwater vehicle toward a water surface. Another exemplary emergency mechanism includes a signaling mechanism configured to signal the underwater vehicle's location.

US Patent:

20050275372, Dec 15, 2005

Filed:

Jun 14, 2005

Appl. No.:

11/151991

Inventors:

Jonathan Crowell - Dorchester MA, US

International Classification:

H02J007/00

US Classification:

320112000

Abstract:

A power controller combines a multitude of smart battery packs into a single large bank, providing balanced charging and discharging. Battery packs are connected in parallel to form groups that may then be connected in series, while the specification limits for current and voltage of individual packs are maintained through microprocessor control of the battery pack charging circuits. The state of each pack is monitored, and charging of a pack at too high a charge is inhibited until the other packs in the group are sufficiently charged to allow balanced current-sharing. The state of each battery is broadcast on a bus to all processors so that each may determine whether there are enough packs of similar charge to safely source a load. The system preferably incorporates management firmware that allows user monitoring of the status of the power subsystem and all connected battery packs.

US Patent:

20090216444, Aug 27, 2009

Filed:

Feb 15, 2007

Appl. No.:

11/675167

Inventors:

Jonathan C. Crowell - Dorchester MA, US

Assignee:

Ocean Server Technology, Inc. - Fall River MA

International Classification:

G01C 21/00
G06F 15/00
G01B 17/00
G01B 11/14

US Classification:

701213, 701207, 702158

Abstract:

A system and a method are provided for determining the position of an underwater vehicle while the vehicle is operating underwater. A buoyant float stays on or near the surface of the water and is attached to the vehicle by thin tether that can include insulated wires. The vehicle moves under the water and pulls the float behind it. The float can receive a localization signal, such as a signal indicating its GPS position, and so can determine its position precisely. The position can be transmitted to the underwater vehicle over the wires located in the tether. The underwater vehicle can use sensors and/or calculations to determine the positional offset of the vehicle from the float buoy and generates its true position based on the known position of the float and the positional offset. The float can be constructed with attributes that will allow the float it operate with a greater tether length, and in turn allow the underwater vehicle to operate at greater depths. The float may also generally carry a radio system for high speed communication of signals from the vehicle while the vehicle is submerged.

US Patent:

46464360, Mar 3, 1987

Filed:

Oct 18, 1985

Appl. No.:

6/788961

Inventors:

Jonathan C. Crowell - Lakeville MA
John T. Swailes - West Islip NY

Assignee:

Kollmorgen Technologies Corporation - Dallas TX

International Classification:

H01K 310

US Classification:

29850

Abstract:

Discloses a method for making a coaxial conductor interconnection circuit board, as well as the board per se, by providing a first conductive coating on a substrate, scribing an insulated wire signal conductor pattern on the first coating and a second conductive coating over the wire to provide a conductive shield surrounding the wire, eliminating conductive material from the coatings in clearance areas at terminal points and drilling at the terminal points by laser beam or mechanical drilling to expose the signal conductor.

US Patent:

20200271780, Aug 27, 2020

Filed:

Jan 28, 2020

Appl. No.:

16/774866

Inventors:

- Fall River MA, US
Jonathan C. Crowell - Dorchester MA, US

International Classification:

G01S 15/66
G01S 3/808
H04B 13/02
G01S 5/22

Abstract:

A system where a large number of underwater devices can transmit their precise position relative to a fixed underwater beacon, by transmitting two short duration, precisely timed acoustic tones (pings). The arrival time of the pulses at the fixed underwater transceiver beacon will relay the transmitter's precise position relative to that beacon. The two pings code for two numbers; either the range and bearing or an X, Y coordinate of each object with respect to the beacon. Data messages can be sent to and received from the beacon, used for command, control and status. The pulses can be a single frequency and have duration of around a 1 ms and operate one or many frequencies to allow multiple cycles to be overlapped in time. This coding scheme allows many devices to send the data simultaneously in the cycle for group tracking from last position or as independent cycles for unambiguous tracking. The transducers used in the system can be omni-directional hydrophones. The tracking grid size is a function of the acoustic frequency chosen and range from 1000 m for 40 KHz and 6000 m for 8 kHz. The system requires that all nodes in the system keep precise synchronized time.

US Patent:

20170235279, Aug 17, 2017

Filed:

May 2, 2017

Appl. No.:

15/584073

Inventors:

- Fall River MA, US
Jonathan C. Crowell - Dorchester MA, US

International Classification:

G04C 11/00
H04L 7/00
G04G 7/00
G01S 19/13
G01V 1/38

Abstract:

Methods and systems for synchronizing clocks used in underwater devices is described. All clocks have some drift due to frequency accuracy and this disclosure provides a method for periodically synchronizing clocks to an accurate master clock to remove long term drift. A synchronization device can use an accurate clock and hardware to transmit both a sound wave and light pulse at the same point in time. Remote slave clocks can detect the light first, and later the sound, allowing them to calculate the distance the pulse had to travel. The clocks can then synchronize their time to the master clock canceling out any drift. The synchronization device can be packaged in a waterproof housing and can be moved around on a periodic basis between the clock on an underwater robot or any other means.